1. Field of the Invention
The present invention relates to a system for processing information for a composite appliance such as a printer, facsimile (FAX), or copying machine.
2. Description of the Related Art
There has conventionally been put to practical use an image processing apparatus called a composite appliance such as a copying machine or facsimile which is equipped with a combination of an image input apparatus such as a scanner and an image output apparatus such as a printer, or a computer system which is equipped with an image input apparatus and image output apparatus as separate component units. To realize composite functions such as an image input function, image output function, and copying function in this image processing apparatus, when the image input apparatus and image output apparatus cannot operate in synchronization with each other, the copying function is realized by outputting, to the image output apparatus, image data temporarily stored from the image input apparatus in a memory. When the image input apparatus and image output apparatus can operate in synchronization with each other, the copying function is realized by disposing a passage for directly transferring an image signal from the image input apparatus to the image output apparatus.
However, the conventional digital composite appliances have been developed by adding the function of a conventional device such that the facsimile function is added to a copying machine or the printer function is added to a facsimile. Such digital composite appliance can only perform composite operations and parallel operations in units of jobs.
In the conventional digital composite appliance, local memories are distributed to interfaces such as a scanner and printer for a case where the use of a bus enough to exchange various processing data for input/output cannot be ensured.
FIG. 112 is a timing chart for explaining job processing under control in units of jobs. Print job 1 and print job 2 are to be processed by a composite appliance. Assume that these jobs are to acquire a given resource (e.g., a page memory). Print job 1 first issued at time T1 acquires the resource. Subsequent print job 2 tries to acquire the resource at timing T2, but fails because the resource is occupied by print job 1. Hence, the resource acquisition request is queued. When print job 1 releases the resource at timing T3, print job 2 acquires the resource in accordance with the queued resource acquisition request of print job 2, and performs processing. That is, print job 1 and print job 2 are serially processed from T1 to T3 because print job 1 exclusively uses the resource.
In the conventional digital composite appliance, a series of job processes are sequentially executed in units of jobs. When a plurality of jobs are input to the digital composite appliance, subsequent jobs wait until a preceding job ends. This decreases the job throughput.
In some cases, memories ensured by distributing them to local devices store repetitive information between the devices. A redundant memory area equal to or larger than a necessary area is required.
When a single CPU executes processes which are different in whether real-time operation is required, processing requiring real-time operation is sacrificed by processing requiring no real-time operation. This decreases the performance of the whole system.
It is an object of the present invention to provide a system which solves any of the above-described problems.
To achieve the above object, according to an aspect of the present invention, an information processing system for a composite appliance, comprises
a first CPU for interpreting a protocol,
job generation means for generating a job on the basis of a result interpreted by the first CPU,
a second CPU for processing the generated job,
means for dividing the generated job into elements in units of pages on the basis of processing by the second CPU,
device management means for managing assignment and release of devices for processing the elements divided in units of pages on the basis of processing by the second CPU, and
means for controlling use of a plurality of busses to process input data and output data in parallel on the basis of processing results of the devices in units of the divided pages.
In the information processing system for a composite appliance, data processing by the first CPU and data processing by the second CPU are preferably divided and independently performed to synchronize the first data processing and second data processing, thereby increasing throughput of data processing.
In the information processing system for a composite appliance, processes by the first and second CPUs are preferably selectively used in accordance with whether real-time operation is required in data processing, thereby increasing throughput of data processing.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.